Set CloudWatchProperties default batch size to API max.

Fixes gh-349
Closes gh-425

Author: bsamartins

spring-cloud-aws-autoconfigure/src/main/java/org/springframework/cloud/aws/autoconfigure/metrics/CloudWatchProperties.java

@@ -24,17 +24,24 @@
  *
  * @author Jon Schneider
  * @author Dawid Kublik
+ * @author Bernardo Martins
  * @since 2.0.0
  */
 @ConfigurationProperties(prefix = "management.metrics.export.cloudwatch")
 public class CloudWatchProperties extends StepRegistryProperties {
 
+	private static final int DEFAULT_BATCH_SIZE = 20;
+
 	/**
 	 * The namespace which will be used when sending metrics to CloudWatch. This property
 	 * is needed and must not be null.
 	 */
 	private String namespace = "";
 
+	public CloudWatchProperties() {
+		setBatchSize(DEFAULT_BATCH_SIZE);
+	}
+
 	public String getNamespace() {
 		return this.namespace;
 	}

spring-cloud-aws-autoconfigure/src/test/java/org/springframework/cloud/aws/autoconfigure/metrics/CloudWatchPropertiesTest.java

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2013-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.aws.autoconfigure.metrics;
+
+import java.util.Properties;
+
+import org.junit.Test;
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.PropertiesPropertySource;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Bernardo Martins
+ */
+public class CloudWatchPropertiesTest {
+
+	@Test
+	public void properties_notSet_shouldHaveDefaultValues() {
+		AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(
+				CloudWatchPropertiesConfiguration.class);
+
+		CloudWatchProperties cloudWatchProperties = applicationContext
+				.getBean(CloudWatchProperties.class);
+		assertThat(cloudWatchProperties.getNamespace()).isEqualTo("");
+		assertThat(cloudWatchProperties.getBatchSize()).isEqualTo(20);
+	}
+
+	@Test
+	public void properties_set_shouldOverrideValues() {
+		Properties properties = new Properties();
+		properties.setProperty("management.metrics.export.cloudwatch.namespace", "test");
+		properties.setProperty("management.metrics.export.cloudwatch.batch-size", "5");
+
+		AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext();
+		applicationContext.getEnvironment().getPropertySources()
+				.addLast(new PropertiesPropertySource("test", properties));
+		applicationContext.register(CloudWatchPropertiesConfiguration.class);
+		applicationContext.refresh();
+
+		CloudWatchProperties cloudWatchProperties = applicationContext
+				.getBean(CloudWatchProperties.class);
+		assertThat(cloudWatchProperties.getNamespace()).isEqualTo("test");
+		assertThat(cloudWatchProperties.getBatchSize()).isEqualTo(5);
+	}
+
+	@Configuration
+	@EnableConfigurationProperties(CloudWatchProperties.class)
+	protected static class CloudWatchPropertiesConfiguration {
+
+	}
+
+}